Submount for optoelectronic, optical, or photonic components

Abstract

An optical submount has a circumscribed 4-faced depression on its bottom surface and a 3-faced depression at an edge of its bottom surface. An optical signal is transmitted through a face of the 3-faced depression and internally reflected from a face of the 4-faced depression. A set of additional depressions and intervening areas on the submount bottom surface act as an alignment mark.

What is claimed is:  
     
       1. An apparatus comprising an optical submount formed from a volume of semiconductor or dielectric material that is substantially transparent over an operational wavelength range, wherein:
 (a) a bottom surface of the submount includes a first 3-faced depression at a forward edge of the bottom submount surface and a 4-faced depression; 
 (b) the submount is arranged to direct or transmit a portion of an optical signal to propagate within the volume of semiconductor or dielectric material between a transmission area of a rearward face of the first 3-faced depression and a transmission area of a top surface of the submount with the optical signal being at least partly internally reflected by a forward face of the 4-faced depression; 
 (c) the 4-faced depression is substantially circumscribed by one or more substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface; and 
 (d) the 4-faced depression is separated from the first 3-faced depression by one of the one or more substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface. 
 
     
     
       2. The apparatus of  claim 1  wherein the bottom surface of the submount includes a second 3-faced depression at a rearward edge of the bottom submount surface, the 4-faced depression is separated from the second 3-faced depression by one of the one or more substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface, and the 4-faced depression is positioned between the first and second 3-faced depressions. 
     
     
       3. The apparatus of  claim 1  wherein the semiconductor or dielectric material comprises a crystalline material, and wherein one or more faces of one or more of the 4-faced and 3-faced depressions substantially coincides with a corresponding crystal plane of the crystalline material. 
     
     
       4. The apparatus of  claim 1  wherein the semiconductor or dielectric material comprises a crystalline material, and the one or more substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface substantially coincide with a corresponding crystal plane of the crystalline material. 
     
     
       5. The apparatus of  claim 1  wherein at least a portion of at least one of the one or more substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface includes a metal coating. 
     
     
       6. The apparatus of  claim 1  further comprising one or more contact areas on the top submount surface that are arranged for attaching a photodetector to the top submount surface in a position that enables the photodetector to receive a transmitted portion of the optical signal that exits the submount through the transmission area of the top submount surface. 
     
     
       7. The apparatus of  claim 1  wherein the transmission area of the top submount surface includes a dielectric anti-reflection layer formed thereon. 
     
     
       8. The apparatus of  claim 1  further comprising a photodetector attached to the top submount surface in a position that enables the photodetector to receive a portion of an optical signal that enters the optical submount through the transmission area of the rearward face of the first 3-faced depression, is internally reflected from the forward face of the 4-faced depression, and exits the optical submount through the transmission area of the top submount surface. 
     
     
       9. The apparatus of  claim 1  wherein the semiconductor or dielectric material is a semiconductor material. 
     
     
       10. The apparatus of  claim 9  wherein the semiconductor material comprises a doped or undoped Group IV semiconductor, a doped or undoped III-V semiconductor, or a doped or undoped II-VI semiconductor. 
     
     
       11. The apparatus of  claim 9  wherein the semiconductor material is doped or undoped silicon. 
     
     
       12. The apparatus of  claim 9  wherein the operational wavelength range is between about 1.2 μm and about 1.7 μm. 
     
     
       13. The apparatus of  claim 1  wherein the semiconductor or dielectric material is a dielectric material. 
     
     
       14. The apparatus of  claim 1  wherein:
 (e) the bottom submount surface includes one or more sets of 4-faced depressions, each set comprising two or more adjacent 4-faced depressions and one or more intervening substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface; and 
 (f) the intervening areas of each set form a corresponding alignment mark arranged for positioning the optical submount on a substrate. 
 
     
     
       15. The apparatus of  claim 14  wherein one or more sets of 4-faced depressions and intervening areas include a metal coating. 
     
     
       16. The apparatus of  claim 14  wherein one or more sets comprise (i) four 4-faced depressions in a rectangular arrangement and (ii) four intervening areas of the bottom submount surface that form a corresponding cross-shaped alignment mark. 
     
     
       17. The apparatus of  claim 14  wherein one or more sets comprise (i) three 4-faced depressions and (ii) two intervening areas of the bottom submount surface that form a corresponding L-shaped or T-shaped alignment mark. 
     
     
       18. The apparatus of  claim 14  wherein one or more sets comprise (i) two 4-faced depressions and (ii) one intervening area of the bottom submount surface that forms a corresponding linear alignment mark. 
     
     
       19. The apparatus of  claim 14  wherein the semiconductor or dielectric material comprises a crystalline material, and wherein one or more faces of one or more 4-faced depressions of one or more sets substantially coincides with a corresponding crystal plane of the crystalline material. 
     
     
       20. An apparatus comprising a first optical element arranged to be attached to a second optical element with an engagement surface of the first optical element on a corresponding engagement surface of the second optical element, wherein:
 (a) the first optical element engagement surface includes one or more sets of 4-faced depressions, each set comprising two or more adjacent 4-faced depressions and one or more intervening substantially flat, substantially horizontal, substantially coplanar areas of the first optical element engagement surface; and 
 (b) the intervening areas of each set form a corresponding alignment mark arranged for positioning the first optical element on the second optical element. 
 
     
     
       21. The apparatus of  claim 20  wherein one or more sets of 4-faced depressions and intervening areas include a metal coating. 
     
     
       22. The apparatus of  claim 20  wherein one or more sets comprise (i) four 4-faced depressions in a rectangular arrangement and (ii) four intervening areas of the bottom submount surface that form a corresponding cross-shaped alignment mark. 
     
     
       23. The apparatus of  claim 20  wherein one or more sets comprises (i) three 4-faced depressions and (ii) two intervening areas of the bottom submount surface that form a corresponding L-shaped or T-shaped alignment mark. 
     
     
       24. The apparatus of  claim 20  wherein one or more sets comprise (i) two 4-faced depressions and (ii) one intervening area of the bottom submount surface that forms a corresponding linear alignment mark. 
     
     
       25. The apparatus of  claim 20  wherein: the first optical element comprises a crystalline material, and wherein: (i) one or more faces of one or more 4-faced depressions of one or more sets substantially coincides with a corresponding crystal plane of the crystalline material, or (ii) each one of the intervening areas of each set substantially coincides with a corresponding crystal plane of the crystalline material. 
     
     
       26. The apparatus of  claim 20  wherein the optical element comprises an optical submount. 
     
     
       27. The apparatus of  claim 9  wherein the semiconductor material comprises a crystalline material, and wherein: (i) one or more faces of one or more of the 4-faced and 3-faced depressions substantially coincides with a corresponding crystal plane of the crystalline material; or (ii) the one or more substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface substantially coincide with a corresponding crystal plane of the crystalline material. 
     
     
       28. The apparatus of  claim 13  wherein the dielectric material comprises a crystalline material, and wherein: (i) one or more faces of one or more of the 4-faced and 3-faced depressions substantially coincides with a corresponding crystal plane of the crystalline material; or (ii) the one or more substantially flat, substantially horizontal, substantially coplanar areas of the bottom submount surface substantially coincide with a corresponding crystal plane of the crystalline material. 
     
     
       29. The apparatus of  claim 16  wherein one or more sets of 4-faced depressions and corresponding one or more cross-shaped alignment marks include a metal coating. 
     
     
       30. The apparatus of  claim 22  wherein one or more sets of 4-faced depressions and corresponding one or more cross-shaped alignment marks include a metal coating.